Concealed automobile glare shield device with sliding groove

ABSTRACT

A sun visor device includes a sun visor including a receiving portion having two guiding grooves at two lateral sides thereof. A glare shield is slidably received in the receiving portion. A track device is disposed in the receiving portion and includes an outer track, a middle track slidably received in the outer track, an inner track slidably received in the middle track and fixed to a supporting rod. Two positioning members are disposed on two ends of the supporting rod, respectively. A pressing member is received in an outer end of each positioning member and is biased outward by a pressing spring to slidably abut an inner wall of an associated guiding groove. Each positioning member further includes a clamping unit fixed to two ends of the glare shield, such that the glare shield is jointly movable with the supporting rod.

BACKGROUND OF THE INVENTION

The present invention relates to a concealed automobile glare shielddevice with a sliding groove and, more particularly, to a concealedautomobile glare shield device that can be concealed in an automobilesun visor with a central sliding groove to achieve smooth operation ofpulling out of or storage in the sun visor, such that a driverencountering glare during driving can conveniently pull out the glareshield to block and filter the glare, thereby enhancing the drivingsafety.

FIG. 6 shows a dashboard C in an interior space I of a vehicle. Thedriver sitting behind the steering wheel SW can see the trafficconditions in front of the vehicle through the windshield FW and can beaware of the traffic conditions behind the vehicle through the rearviewmirror RM and the two side view mirrors SM. When encountering lightincident through the windshield FW, the driver generally moves the sunvisor 10 to a position blocking the light. However, the conventional sunvisor 10 is not transmittable to light and, thus, should not be toolarge to adversely affect the driving safety. Aside from the dangercaused by an excessively large sun visor 10 that blocks the eyesight inthe limited interior space I of the vehicle, the driver has to move thesun visor 10 to a position trying to possibly block the glare accordingto the area of the sun visor 10 without blocking the whole eyesight. Itis therefore a general problem to provide both the desired glareblocking effect and the driving safety.

In an approach to fulfill the need of improving driving safety whileeffectively filtering glare during driving using the conventional sunvisor that is not transmittable to light and that must be restricted ina certain safety area, a light-transmittable glare shield is clipped tothe sun visor. When encountering glare, the driver can pivot the glareshield at a side of the sun visor downward to shield the eyes from thelight, increasing the driving safety. However, the glare shield clippedto the sun visor is visually protrusive and would block a make-up mirrorand a night lamp, if any, disposed on the sun visor.

U.S. Pat. No. 5,662,371 discloses a sun visor light reducer extensionhaving a three-sided rigid frame capable of being incorporated within avehicle's sun visor. A glare shield is received in a groove defined bythe rigid frame and has a pair of guide stops protruding slightly upwardfrom its surface. An elastic urging member is disposed between twopivoted leg segments of the rigid frame. Each leg segment has a stoppingtab extending inward. The stopping tabs act as a stopping means duringdischarge of the glare shield by forming a barrier when impinged againstthe guide stops. However, the resultant structure has a significantthickness and, thus, limits its practical utility. Furthermore, theguide stops can only prevent the glare shield from falling out of thesun visor, but the glare shield lacks mechanisms for abutting againstthe inner edge of the groove in the three-sided rigid frame, failing toprovide lateral resistance. Thus, the glare shield cannot be preciselypositioned and could even fall off. Furthermore, in the sliding supportmechanism at the two lateral sides of the glare shield, the wider theglare shield, the longer the unbalanced force components at the twolateral sides when pulling the glare shield. The unbalanced forcecomponents cause shear force, such that a side is pressed while theother side slackens. After repeated pulling, the two lateral sides ofthe glare shield are worn to different extents and are, thus, apt todisengage. Thus, the glare shield cannot be positioned easily duringdisplacement and, thus, cannot be used.

U.S. Pat. No. 4,828,314 discloses a visor with retractable glareshields. The visor includes a center board defining guide slots forreceiving glare screens. A slot follower is disposed within one of theguide slots for guiding purposes. However, when pushing a glare screenby the central portion, the resistances at the two lateral sides causean excessively large stress at the central portion, leading todifficulties in pushing. Thus, a user has to pull the glare screen witha larger force during operation, leading to larger wear extent betweenthe follower and the guide slot. Specifically, due to the directfrictional contact between the lateral sides of the follower and theinner walls of the guide slot, gaps due to wear are generated afterrepeated use. The gaps make the pushing operation more unstable,aggregating the physical-contact wear.

Since the conventional techniques cannot effectively solve the twoissues of stable sliding and wear of the concealed glare shield receivedin the sun visor, there are not many sun visors with concealed glareshields on the market. This is because conventional designs cannot solvethe two issues at the same time.

BRIEF SUMMARY OF THE INVENTION

In a first aspect according to the present invention, a sun visor devicecomprises:

a sun visor including a receiving portion having two lateral sides,wherein each of the two lateral sides includes a guiding groove;

a glare shield received in the receiving portion; and

a track device disposed in the receiving portion and including an outertrack, a middle track, and an inner track supporting portion, whereinthe middle track is received in and slidably abuts the outer track,wherein the inner track supporting portion includes an inner track, twopositioning members, and a supporting rod, wherein the inner track isfixed to the supporting rod, wherein the two positioning members aredisposed on two ends of the supporting rod, respectively, wherein eachof the two positioning members includes a pressing spring received in acentral portion thereof and a pressing member received in an outer endthereof, wherein the pressing spring biases the pressing member outwardsto provide the pressing member with an outward pressing force, such thatthe pressing member slidably abuts an inner wall of an associatedguiding groove of the sun visor, and wherein each of the two positioningmembers further includes a clamping unit fixed to two ends of the glareshield, such that the glare shield is jointly movable with thesupporting rod to make the inner track slide relative to the sun visor.

In an example, the receiving portion includes an open side and areceiving groove in a central portion thereof. The receiving groove isrecessed into a surface of the receiving portion to include a depth. Theouter track of the track device is securely received in the receivinggroove.

In an example, each guiding groove includes a protrusion and apositioning hole on an inner end thereof relative to the sun visor.

In an example, a lid is disposed to a connecting face on a top face ofan outer edge of the receiving portion. A space defined by the receivingportion covered by the lid is slightly larger than a sum of a thicknessof the glare shield and a thickness of the track device, avoiding wearto the glare shield when sliding in the receiving portion.

In an example, two sides of the middle track are two sliding sides witha plurality of balls. The two sliding sides slidably abut two tracksides of the outer track. A length of the middle track is smaller than alength of the outer track. The middle track does not extend beyond thelength of the outer track during sliding.

In an example, the inner track is an inverted track including twoabutting sides which are disposed between and slidable along the slidingsides of the middle track. A length of the inner track is smaller than alength of the middle track. The inner track, the middle track, and theouter track are received in the depth of the receiving groove afterassembly.

In an example, each of the two positioning members includes a pressingand holding member in a form of a hollow tube. An adjusting screw is inthreading connection with an inner end of the pressing and holdingmember. The pressing spring received in a central portion of thepressing and holding member. The adjusting screw is rotatable toslightly adjust elasticity of the pressing spring, providing thepressing member with different outward pressing forces.

In a second aspect according to the present invention, a sun visordevice comprises:

a sun visor including a receiving portion having an open side, whereinthe receiving portion further includes a receiving groove in a centralportion thereof, wherein the receiving portion further includes havingtwo lateral sides, and wherein each of the two lateral sides includes aguiding groove;

a glare shield received in the receiving portion; and

a track device disposed in the receiving groove and including an outertrack, a middle track, and an inner track supporting portion, whereinthe outer track is fixed in the receiving groove, wherein the middletrack is received in and slidably abuts the outer track, wherein twosides of the middle track are two sliding sides with a plurality ofballs, wherein the two sliding sides slidably abut two track sides ofthe outer track, wherein a length of the middle track is smaller than alength of the outer track, and wherein the middle track does not extendbeyond the length of the outer track during sliding,

wherein the inner track supporting portion includes an inner track, twopositioning members, and a supporting rod, wherein the inner track is aninverted track including two abutting sides which are disposed betweenand slidable along the sliding sides of the middle track, wherein alength of the inner track is smaller than the length of the middletrack, and wherein the inner track, the middle track, and the outertrack are received in the depth of the receiving groove after assembly,

wherein a top end of the inner track is fixed to the supporting rod,wherein the supporting rod is received in the receiving portion of thesun visor, wherein the two positioning members are disposed on two endsof the supporting rod, respectively, wherein each of the two positioningmembers slidably abuts an inner wall of an associated guiding groove ofthe sun visor, and wherein the two positioning members are fixed to twoends of the glare shield, such that the glare shield is jointly movablewith the supporting rod to make the inner track slide relative to thesun visor.

In an example, when the glare shield is pulled outward, the two slidingsides of the middle track are actuated via the inner track to slidealong the outer track. The moving speed of the inner track is fasterthan the moving speed of the two sliding sides of the middle track onthe two track sides of the outer track, providing the glare shield witha larger extension travel.

In an example, the receiving groove is recessed into a surface of thereceiving portion to include a depth.

In an example, each guiding groove includes a protrusion and apositioning hole on an inner end thereof relative to the sun visor.

In an example, a lid is disposed to a connecting face on a top face ofan outer edge of the receiving portion. A space defined by the receivingportion covered by the lid is slightly larger than the sum of athickness of the glare shield and a thickness of the track device,avoiding wear to the glare shield when sliding in the receiving portion.

In an example, a side of a top end of the inner track at the open end ofthe receiving portion is fixed perpendicularly to the supporting rod.The supporting rod is fixed to the top end of the inner track at alocation. The location and another end of the inner track have a depththerebetween.

In an example, each of the two positioning member includes a pressingand holding member, an adjusting screw in threading connection with aninner end of the pressing and holding member, a pressing spring receivedin a central portion of the pressing and holding member, and a pressingmember received in an outer end of the pressing and holding member. Theadjusting screw is rotatable to slightly adjust elasticity of thepressing spring, providing the pressing member with different outwardpressing forces.

In an example, each of the two positioning members further includes aclamping unit having a clamping portion fixed to an associated one ofthe two ends of the glare shield.

The present invention will become clearer in light of the followingdetailed description of illustrative embodiments of this inventiondescribed in connection with the drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a sun visor device using aconcealed automobile glare shield device of a preferred embodimentaccording to the present invention.

FIG. 1A is an enlarged view of a circled portion of FIG. 1, showing aportion of a positioning member.

FIG. 1B is an enlarged view of another circled portion of FIG. 1,showing a portion of a positioning portion of a guiding groove.

FIG. 2 is a perspective view of the concealed automobile glare shielddevice of the preferred embodiment in a storage position.

FIG. 2A is a cross sectional view taken along section line A-A′ of FIG.2.

FIG. 3 is a perspective view of the concealed automobile glare shielddevice of the preferred embodiment in a storage position.

FIG. 3A is cross sectional view taken along section line A-A′ of FIG. 3.

FIG. 4 is a partly-exploded perspective view of the sun visor device ofthe preferred embodiment in the storage position.

FIG. 5 is a partly-exploded perspective view of the sun visor device ofthe preferred embodiment in an extended position.

FIG. 6 is illustrating a portion of an interior space of a vehicle.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an exploded, perspective view of a sun visor device using aconcealed automobile glare shield device of a preferred embodimentaccording to the present invention. To effectively solve the issue ofthe concealed glare shield in a sun visor 10 regarding inconvenientoperation caused by the wear and resistance resulting from slidingmovement at the two lateral sides or at the central portion, the sunvisor device according to the present invention is featured by that asliding device 20 is disposed in a receiving groove 102 in a centralportion of the sun visor 10, providing a positional width W to balancethe sliding movements at two lateral sides during operation.Furthermore, the sliding device 20 includes ball-supported three tracksto double the displacement, such that the whole sliding movement issmooth, thereby significantly reducing the resistance and wear.

FIG. 1A is an enlarged view of a circled portion of FIG. 1, showing aportion of a positioning member. FIG. 1B is an enlarged view of anothercircled portion of FIG. 1, showing a portion of a positioning portion ofa guiding groove. The sun visor device using the concealed automobileglare shield device of the preferred embodiment according to the presentinvention comprises a sun visor 10 serving as a body. The sun visor 10includes a receiving portion 101 having an interior space in which aglare shield 30 is telescopically received. The receiving portion 101has an open side at an end thereof, permitting the glare shield 30 tomove into or out of the receiving portion 101. In this preferredembodiment, the receiving portion 101 includes a receiving groove 102 ina central portion thereof. The receiving groove 102 has a length L1. Thereceiving groove 102 is recessed into a surface of the receiving portion101 to include a larger depth. The receiving groove 102 includes twogroove walls 1021 having a positioning width W (see FIG. 5) therebetweenthroughout the depth thereof. The interior space of the receivingportion 101 includes two lateral sides that are wider. Each of the twolateral sides of the receiving portion 101 has a guiding groove 103. Theguiding grooves 103 are symmetric to each other. Each guiding groove 103includes an inner end opposite to the open side of the sun visor 10. Theinner end of each guiding groove 103 includes a protrusion 1031 and apositioning hole 1032. The sun visor 10 includes a connecting face 104at a top face of an outer edge of the receiving portion 101.

The preferred embodiment according to the present invention is featuredby that a track device 20 is disposed in the receiving groove 102. Thetrack device 20 includes an outer track 21, a middle track 22, and aninner track supporting portion 23. The outer track 21 is a sliding trackformed by pressing metal. The outer track 21 includes two track sides211 opposite to each other. The outer track 21 is inserted into andfixed in the two groove walls 1021 and has a length L2 slightly smallerthan the length L1 of the receiving groove 102. Each of two ends of thelength L2 of the outer track 21 has an abutting end 212. The middletrack 22 is disposed between the two track sides 211 of the outer track21 and is substantially U-shaped. Each of two sides of the middle track22 is a sliding side 221 with a plurality of balls. Each sliding side221 abuts an associated one of the two track sides 211 of the outertrack 21. The middle track 22 has a length L3 smaller than a half of thelength L2 of the outer track 21. When sliding, the middle track 22 willnot slide beyond the length L2 of the outer track 21.

The inner track supporting portion 23 includes an inner track 231, twopositioning members 232, and a supporting rod 233. The inner track 231is inverted U-shaped and has two abutting sides 2311. The two abuttingsides 2311 slides along the sliding sides 221 with balls of the middletrack 22. The inner track 231 has a length L4 smaller than the length L3of the middle track 22. Furthermore, after assembly, the inner track231, the middle track 22, and the outer track 21 are located in thedepth of the receiving groove 102 of the receiving portion 101. A sideof a top end of the inner track 231 at the open side of the receivingportion 101 is fixed perpendicularly to the supporting rod 233. Thesupporting rod 233 is fixed to the top end of the inner track 231 at alocation. The location and another end of the inner track 231 have adepth D therebetween. The supporting rod 233 is located in the receivingportion 101 of the sun visor 10. The two positioning member 232 aredisposed on two ends of the supporting rod 233, respectively.

In this preferred embodiment, each of the two positioning members 232includes a pressing and holding member 2321 in the form of a hollowtube. An adjusting screw 2324 is in threading connection with an innerend of the pressing and holding member 2321 facing a center of thesupporting rod 233. A pressing spring 2323 is received in a centralportion of the pressing and holding member 2321. A pressing member 2322is disposed in an outer end of the pressing and holding member 2321. Theadjusting screw 2324 can be rotated to slightly adjust the elasticity ofthe pressing spring 2323, providing the pressing member 2322 at theother end of the pressing spring 2323 with different outward pressingforces. The pressing member 2322 slidably presses against the guidinggroove 103 of the sun visor 10. Each of the two positioning members 232further includes a clamping unit 2325 having a clamping portion 2326fixed to an associated one of the two ends of the glare shield 30. Thus,the supporting rod 233 and the glare shield 30 are jointly movable tomake the inner track 231 slide relative to the sun visor 10.

FIG. 2 is a perspective view of the concealed automobile glare shielddevice of the preferred embodiment in a storage position. FIG. 2A is across sectional view taken along section line A-A′ of FIG. 2. Due to thelimitation in the thickness and the length of the sun visor 10 in aninterior space of an automobile, one of the features of the presentinvention resides in that the glare shield 30 and the track device 20are coupled together in an upper/lower relationship by the twopositioning members 232. The receiving portion 101 and the receivinggroove 12 are disposed in a vertical relationship in the sun visor 10 ofa limited length to receive the glare shield 30 and the track device 20,such that a most compact structure in the upper/lower relationship and amaximal forward/rearward sliding space are provided. Thus, the glareshield 30 can move into or out of the receiving portion 101 of the sunvisor 10 while obtaining the smoothest sliding/positioning effect andavoiding wear at the same time. When the glare shield 30 is received inthe receiving portion 101 of the sun visor 10, the top end of the innertrack 231 adjacent to the open side of the receiving portion 101 isfixed to the supporting rod 233 in a vertical direction, such that theglare shield 30 has a maximal exposed area ratio in the extendedposition and can be completely received in the receiving portion 101 ofthe sun visor 10. When the glare shield 30 is received in the sun visor10, the outer track 21, the middle track 22, and the inner track 231 ofthe track device 20 are in a position in which the outer track 21 abutsthe inner edge of the receiving groove 102 by a side of the abutting end212.

When the glare shield 30 is pulled outward to the extended position, theabutting sides 2311 of the inner track 231 contact with and actuate thetwo sliding sides 221 with balls at two sides of the middle track 22 toslide. The two sliding slides 221 of the middle track 22 slide on thetwo track sides 211 of the outer track 21 by the balls. The moving speedof the inner track 231 is faster than the moving speed of the twosliding sides 221 of the middle track 22 on the two track sides 211 ofthe outer track 21. Thus, the glare shield 30 has a larger extensiontravel, and the ratio of the travel to length L2 of the outer track 21can be smaller. The length L3 of the middle track 22 provides supportfor sliding contact for the abutting sides 2311 of the inner track 231.The length L4 of the inner track 231 withstands the stress imparted tothe track device 20 resulting from the clamping of the sun visor 30 bythe clamping units 2325 on the two ends of the supporting rod 233.

FIG. 3 is a perspective view of the concealed automobile glare shielddevice of the preferred embodiment in a storage position. FIG. 3A iscross sectional view taken along section line A-A′ of FIG. 3. When theglare shield 30 is pulled outward to an end of its travel (i.e., theextended position), the inner track 231 and the middle track 22 move toa position adjacent to the abutting end 212 of the outer track 21 at theopen end of the receiving groove 102. The length L4 of the inner track231 reliably supports the glare shield 30 extended outside of the sunvisor 10. The glare shield 30 is a board with a thickness. In apreferred embodiment, the glare shield 30 is not limited to a boardpermeable or impermeable to light. In a case of a light-permeable board,the board can be made of a material capable of filtering light. Inanother case of a light-impermeable board, the board is used to increasethe light-blocking area.

FIG. 4 is a partly-exploded perspective view of the sun visor device ofthe preferred embodiment in the storage position. FIG. 5 is apartly-exploded perspective view of the sun visor device of thepreferred embodiment in an extended position. After the glare shield 30and the track device 20 are mounted in the sun visor 10, the glareshield 30 can be completely received in the compartment 101 through theoperation of the track device 20. Furthermore, the clamping units 2325on the two sides of the supporting rod 233 permit the glare shield 30 tomove between an extended position or the storage position in thereceiving portion 101. It is noted that the glare shield 30 securelyclamped by the clamping units 2325 on two sides of the supporting rod233 have a maximum positioning width without clamping or pressing by thesun visor 10, thereby avoiding wear. Furthermore, the supporting rod 233smoothly slides on the track device 20 to proceed with movement betweenthe extended position and the storage position by the rolling contact(which causes minimal wear) of the inner track 231 through the balls,such that the operation is both smooth and reliable. The sun visor 10can be securely held by the two clamping units 2325 by threadingconnection or bonding. The width of the sun visor 10 can be of a sizepermitting the two edges of the sun visor 10 to be selectively insertedor not inserted into the guiding grooves 103 for sliding purposes.

Furthermore, each of the guiding grooves 103 at two sides of thereceiving portion 101 can selectively include a protrusion 1031 and apositioning hole 1032 at the inner end or the open end of the guidinggroove 103. When the pressing member 2322 of each positioning member 232is at either end of the travel in the associated guiding groove 103 ofthe sun visor 10, the protrusion 1031 provides a sense of resistancewhile pushing, such that the operator can feel the travel is near itsend. The positioning hole 1032 of an associated protrusion 1031 at anend of the travel of the guiding groove 103 restricts further movementof the pressing member 2322 of the associated positioning member 232,providing a positioning effect. A lid 11 is disposed on the connectingface 104. The space formed after the lid 11 is disposed on the receivingportion 101 is slightly larger than the sum of the thickness of theglare shield 30 and the track device 20 to avoid wear to the glareshield 30 when sliding in the receiving portion 101.

It can be appreciated that each of the two ends of the supporting rod233 can also include a pressing spring 2323 mounted around a centralportion thereof and a pressing member 2322 mounted to an outer endportion thereof, with the pressing spring 2323 biasing the pressingmember 2322 outward to slidably abut the wall of the associated guidinggroove 103 of the sun visor 10. Furthermore, the guiding grooves 103 attwo sides of the receiving portion 101 can selectively include aplurality of protrusions 1031 or positioning holes 1032 to provide aplurality of travel sections. The length of the glare shield 30 can beset to be received or partially protrude beyond the receiving portion101. Based on the setting of the total width, the sun visor 10 caninclude a plurality of receiving grooves 102 in the receiving portion101 to receive a corresponding number of track devices 20 for connectingwith the same supporting rod 233 for the purposes of supporting a widersun visor 10 and a wider glare shield 30, providing support for a largerarea.

In view of the foregoing, the sun visor device using the concealedautomobile glare shield device according to the present inventionprovides the driver with an aesthetic sun visor 10 with an extendedshielding effect while achieving the best glare shield receivingefficiency and smooth operation as well as significantly reducing wear.

Although specific embodiments have been illustrated and described,numerous modifications and variations are still possible withoutdeparting from the scope of the invention. The scope of the invention islimited by the accompanying claims.

The invention claimed is:
 1. A sun visor device comprising: a sun visorincluding a receiving portion having two lateral sides, wherein each ofthe two lateral sides includes a guiding groove; a glare shield receivedin the receiving portion; and a track device disposed in the receivingportion and including an outer track, a middle track, and an inner tracksupporting portion, wherein the middle track is received in and slidablyabuts the outer track, wherein the inner track supporting portionincludes an inner track, two positioning members, and a supporting rod,wherein the inner track is fixed to the supporting rod, wherein the twopositioning members are disposed on two ends of the supporting rod,respectively, wherein each of the two positioning members includes apressing spring received in a central portion thereof and a pressingmember received in an outer end thereof, wherein the pressing springbiases the pressing member outwards to provide the pressing member withan outward pressing force, such that the pressing member slidably abutsan inner wall of an associated guiding groove of the sun visor, andwherein each of the two positioning members further includes a clampingunit fixed to two ends of the glare shield, such that the glare shieldis jointly movable with the supporting rod to make the inner track sliderelative to the sun visor.
 2. The sun visor device as claimed in claim1, wherein the receiving portion includes an open side and a receivinggroove in a central portion thereof, wherein the receiving groove isrecessed into a surface of the receiving portion to include a depth, andwherein the outer track of the track device is securely received in thereceiving groove.
 3. The sun visor device as claimed in claim 1, whereineach guiding groove includes a protrusion and a positioning hole on aninner end thereof relative to the sun visor.
 4. The sun visor device asclaimed in claim 1, wherein a lid is disposed to a connecting face on atop face of an outer edge of the receiving portion, and wherein a spacedefined by the receiving portion covered by the lid is slightly largerthan a sum of a thickness of the glare shield and a thickness of thetrack device, avoiding wear to the glare shield when sliding in thereceiving portion.
 5. The sun visor device as claimed in claim 1,wherein two sides of the middle track are two sliding sides with aplurality of balls, wherein the two sliding sides slidably abut twotrack sides of the outer track, wherein a length of the middle track issmaller than a length of the outer track, and wherein the middle trackdoes not extend beyond the length of the outer track during sliding. 6.The sun visor device as claimed in claim 1, wherein the inner track isan inverted track including two abutting sides which are disposedbetween and slidable along the sliding sides of the middle track,wherein a length of the inner track is smaller than a length of themiddle track, and wherein the inner track, the middle track, and theouter track are received in the depth of the receiving groove afterassembly.
 7. The sun visor device as claimed in claim 1, wherein each ofthe two positioning members includes a pressing and holding member in aform of a hollow tube, wherein an adjusting screw is in threadingconnection with an inner end of the pressing and holding member, whereinthe pressing spring received in a central portion of the pressing andholding member, and wherein the adjusting screw is rotatable to slightlyadjust elasticity of the pressing spring, providing the pressing memberwith different outward pressing forces.
 8. A sun visor devicecomprising: a sun visor including a receiving portion having an openside, wherein the receiving portion further includes a receiving groovein a central portion thereof, wherein the receiving portion furtherincludes having two lateral sides, and wherein each of the two lateralsides includes a guiding groove; a glare shield received in thereceiving portion; and a track device disposed in the receiving grooveand including an outer track, a middle track, and an inner tracksupporting portion, wherein the outer track is fixed in the receivinggroove, wherein the middle track is received in and slidably abuts theouter track, wherein two sides of the middle track are two sliding sideswith a plurality of balls, wherein the two sliding sides slidably abuttwo track sides of the outer track, wherein a length of the middle trackis smaller than a length of the outer track, and wherein the middletrack does not extend beyond the length of the outer track duringsliding, wherein the inner track supporting portion includes an innertrack, two positioning members, and a supporting rod, wherein the innertrack is an inverted track including two abutting sides which aredisposed between and slidable along the sliding sides of the middletrack, wherein a length of the inner track is smaller than the length ofthe middle track, and wherein the inner track, the middle track, and theouter track are received in the receiving groove after assembly, whereina top end of the inner track is fixed to the supporting rod, wherein thesupporting rod is received in the receiving portion of the sun visor,wherein the two positioning members are disposed on two ends of thesupporting rod, respectively, wherein each of the two positioningmembers slidably abuts an inner wall of an associated guiding groove ofthe sun visor, and wherein the two positioning members are fixed to twoends of the glare shield, such that the glare shield is jointly movablewith the supporting rod to make the inner track slide relative to thesun visor.
 9. The sun visor device as claimed in claim 8, wherein whenthe glare shield is pulled outward, the two sliding sides of the middletrack are actuated via the inner track to slide along the outer track,and wherein a moving speed of the inner track is faster than a movingspeed of the two sliding sides of the middle track on the two tracksides of the outer track, providing the glare shield with a largerextension travel.
 10. The sun visor device as claimed in claim 8,wherein the receiving groove is recessed into a surface of the receivingportion to include a depth.
 11. The sun visor device as claimed in claim8, each guiding groove includes a protrusion and a positioning hole onan inner end thereof relative to the sun visor.
 12. The sun visor deviceas claimed in claim 8, wherein a lid is disposed to a connecting face ona top face of an outer edge of the receiving portion, and wherein aspace defined by the receiving portion covered by the lid is slightlylarger than a sum of a thickness of the glare shield and a thickness ofthe track device, avoiding wear to the glare shield when sliding in thereceiving portion.
 13. The sun visor device as claimed in claim 8,wherein a side of a top end of the inner track at the open end of thereceiving portion is fixed perpendicularly to the supporting rod,wherein the supporting rod is fixed to the top end of the inner track ata location, and wherein the location and another end of the inner trackhave a depth therebetween.
 14. The sun visor device as claimed in claim8, wherein each of the two positioning member includes a pressing andholding member, an adjusting screw in threading connection with an innerend of the pressing and holding member, a pressing spring received in acentral portion of the pressing and holding member, and a pressingmember received in an outer end of the pressing and holding member, andwherein the adjusting screw is rotatable to slightly adjust elasticityof the pressing spring, providing the pressing member with differentoutward pressing forces.
 15. The sun visor device as claimed in claim 8,wherein each of the two positioning members further includes a clampingunit having a clamping portion fixed to an associated one of the twoends of the glare shield.